Graphene, Polylactic acid, Bioplastic, Stearic acid For the purpose of development of graphene/polylactic acid (PLA) composites with improved mechanical properties, a stearic acid (SA) compatibilizer was used to enhance the compatibility of graphene oxide sheets (GO) to PLA polymer matrix. Graphene oxide was modified with stearic acid at different mass ratios of 1, 3 and 5 prior to forming composites with PLA. Characterization showed positive effects of SA attached to GO in every mass ratio and also compatibility with PLA matrix. SA can strengthen interfacial interactions of flat graphene sheets with polymer matrices resulting in polymer properties improvement. The tensile strength of PLAGO-SA composites with mass ratio of 1 increases almost 35 percent compared to neat PLA. The results implied that GO-SA composites can be used as a nanosheet filler for property enhancement in PLA.